Phone numbers in Belfast, New York
Belfast has 3 phone prefixes in area code 585.
Biggest holders: Verizon (local phone), AT&T Mobility, Onvoy. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 33%
- Local phone company 33%
- Internet / business phone carrier 33%
Every prefix in Belfast
Search the first six digits of a number in this list. If it's here, the number started in Belfast with the carrier shown. If it isn't, check the New York page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 585-365 | Verizon (local phone) | Local phone company | – |
| 585-628 | AT&T Mobility | Mobile carrier | 2014 |
| 585-858 | Onvoy | Internet / business phone carrier | 2021 |
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number. Source: NANPA central office code records, 2026-10-10.